Phosphoric-acid baking-powder.



TATES PATENT Onrrcn.

PHILIP B. HUNT, OF MINNEAPOLIS, MINNESOTA.

PHOSPHORlC-ACID BAKING-POWDER.

SPECIFICATION forming part of Letters Patent No. 654,572, dated July 24,1900.

I Application filed June 21, 1900. Serial No. 21,123. (No specimens.)

and useful Improvements in Phosphoric-Acid Baking-Powder, of which thefollowing is a specification.

This invention relates to phosphatic baking powders and preparations;and the ob- 1o ject of the invention is to provide a bakingpowders.

, to the atmosphere.

powder of the phosphatic order which will possess superior keepingqualities and which will be of a substantially-fixed strength orcharacter.

As is well known to all familiar with the art of baking-powders, suchpreparations are peculiarly liable to deterioration when exposed toatmospheric influences, and this is markedlythe case with all phosphaticbaking- Phosphoric-acid baking-powders have all included as a principalingredient sodium carbonate or bicarbonate. In most instancesbicarbonate and the phosphoricacid material have been in afinely-pulverulent condition, and powders thus constituted have beennoted for a far-too-ready solubility in water preparatory to the use ofthe powder in food and have also been noted for quick decomposition ordeterioration when exposed This characteristic of phosphatic bakingpreparations has greatly reduced their commercial value when comparedwith baking-powders containing a more staple acidifying agent. Theforegoing statements are also true of phosphatic baking-powders whereinthe phosphoric-acid material has appeared in the form of coarse grainsor granules essentially or substantially free from pulverulentphosphatic material, except that such have been somewhat less quicklyperishable than the other phosphatic powders and havein consequencecommanded a somewhat-higher price and standing inthe market. For powdersof the latter class the phosphatic material is prepared by elaborateprocesses, whereby all fine particles of phosphate are rejected, onlyuniform large particles or granules being retained in the powder; Whilethis material is more costly than the very-fine phosphate, its use iscertainly desirable, as experience shows that powders containing thesame hold their leavening strength for longer periods.

The particular object of my invention is to still further guardphosphatic baking-powders against decomposition and increase the keeping qualities thereof. This I accomplish by a physical change in thealkaline constituent of the powder. Acid phosphate is amorphous and isnot dense in structure. It hasa strong affinity for and is easilyattacked by moisture, and in this respect it is detrimental to anypowder wherein it is used. On the other hand, sodium carbonate andsodium bicar-.

bonate are of adense solid character, not

particularly deliquescent or hygroscopic.

Proceeding from a knowledge of these princi pal ingredients ofphosphatic baking-powders my conception of an enduring baking-powder isa baking-powder wherein the hygroscopic qualities of the acidifyingagent are practically ignored and dependence for stabilityis placed onthe alkaline element of the powder, which is so prepared as tocounteract the quick absorption of moisture by the phosphatic materialand consequent evolution of carbonic-acid gas before the powder is used.

-While, as before explained, granular phos phate does to a considerableextent deter the loss of leavening power, I havediscovered thatdeterioration and loss of power in such baking-powders is hastenedundesirably and unnecessarily by the minute subdivision of the alkalinecarbonate or bicarbonate, such as sodium bicarbonate. The very finenessof this material renders it almost as easily per meable and soluble bymoisture as is the amorphous phosphatic element of the powder. Opposedto this condition in all phosphatic powders hitherto suggested I havediscovered that by employing only coarse and large grains or crystals ofsodium carbonate or bicarbonate in place of the usual fine product andin admixture with granular phosphate I obtain a baking-powder which ispractically indestructible by exposure to the atmosphere,

even though after long exposure the phos phat-i0 material becomesquite-thoroughly saturated with moisture.

My invention therefore consists in a baking powder or preparationcomprising sodium carbonate or bicarbonate in a coarsely-gram ulatedcondition in admixture with granular phosphatic material and a suitablediluent or diluents, the mixture being essentially free from pulverulentphosphatie material. The granules of alkaline material may correspond insize to the granules of acid material usually employed and known asspecial or granular phosphate but I have employed even coarser granulesor crystals of sodium carbonate and bicarbonate.

The increased stability of my baking-powder is accounted for by theincreased density of the body of sodium carbonate or bicarbonate takenas a whole as present in a given quantity of the powder; also, by thelarge reduction in extent of the surface of the carbonate or bicarbonateexposed to moisture; also, in the reduction of the number of pointsofcontact between the alkaline and acid elements of the powder, and,finally, by the protection of the granules or crystals of bicarbonate bythe fine or pulverulent diluent which practically covers the surfacesthereof. Experiments have proven that my bakingpowder retains almost allof its initial leavening power even after long periods of exposure tothe atmosphere, and have also proven that my baking-powder does notreadily cake or become solid in the cans wherein it is packed, and,further, that when my baking-powder is moistened preparatory to use inbread sufficient gas is evolved for the dough, while the mixturethereafter retains enough leavening strength to thoroughly lighten thebread after it is placed in the oven.

Having thus described my invention, I claim as new anddesire to secureby Letters Patent- 1. A phosphoric -acid baking powder or preparationcontaining an alkaline carbonate or bicarbonate in granular conditionadmixed with phosphatic material,also in granular condition, andessentially free from pulverulent phosphatic material.

2. A baking powderor preparation containing sodium carbonate orbicarbonate in coarse grains or granules, admixed with special orgranular acid phosphate in a like condition and essentially free frompulverulent phosphatic material.

3. A baking-powder comprising acid and alkaline materials in a conditionof coarse grains or granules essentially free from pulverulent alkalineor acid materials, and a suitable pulverulent diluent or diluents.

In testimony whereof I have hereunto set my hand this 12th day of June,1900, at Minneapolis, Minnesota.

PHILIP B. HUNT.

In presence of- G. G. HAWLEY, M. E. GOOLEY.

